FAQ: Gas Density Monitors & Sensors

Do you have any questions on gas density monitors or sensors?
First answers can be found here in our FAQ.

If you have further questions, do not hesitate to contact us.
Our product manager for gas density will be happy to answer your questions.

 

Display options for gas density monitors

 

Trafag provides maximum flexibility in customization for the indicator dial with a full variety of colour codings and pressure units including dual range indication. This also includes rotated dial orientation by 90°/180°/270° to provide best readability for restricted installations.

 

An optional low-pressure indicator monitors conditions aside normal operation e.g. while compartment is filled with transport pressure or being vacuumed.

Gas density monitors in arctic climate

 

Arctic climate presents the highest requirements to gas compartment and density monitoring. The main safety aspect is the alarm when the insulating gas may liquefy.

 

Low temperatures can lead to liquefaction of process gas. Liquefaction causes a rapid pressure-drop that can temporarily trigger an alarm switchpoint. Gas density monitor 87x8 keeps the alarm status until the alarm trigger level is exceeded again while returning to normal condition.

Signal outputs for gas density sensors

The digital pulse-width modulation features density and temperature data. Trafag provides conversion formulas for gas density, standardised gas pressure @ 20°C for SF6 or alternative insulating gases and for the conversion of pulse-width to temperature.

 

The current loop output has a resolution of 6.5 … 20 mA. Trafag provides conversion formulas for gas density and standardised gas pressure @ 20°C for SF6 and alternative insulating gases.

Modbus communication for gas density sensors

The open available Modbus protocol is the ideal communication layer for transmitting data between electronic devices over serial RS485 lines. It is a client/ server protocol. One client controls the data transactions with multiple servers (sensors) that respond to the client's requests (read or write data). In a standard Modbus serial network, there is one client and up to 64 servers (sensors), each with a unique server address.

Gas density measurement for preventive maintenance

Density measurement is provided via 2-wire current loop output. It provides essential trend information of potential gas losses or gear status and therefore allows to determine preventive maintenance measures.

Density monitoring is based on up to three galvanically isolated microswitches that actuate different alarm signals.

Test valve functionality for gas density monitors

Integrated density monitor test valve

Greenhouse regulations require regular verifications of the used equipment. The test valve allows in-situ microswitch point or sensor checkings without dismounting the monitor from the pressure compartment. Test equipment is connected via a standardised DN8 port during normal operation under nominal system pressure.

Process gas test and re-fill valve functionalities for gas density monitors

Integrated process gas test and re-fill valve

The test and re-fill valve offers two essential functionalities. Firstly, it provides the capability to analyze in-situ the gas quality of the pressure compartment. On the other hand, it is a re-filling valve that allows direct insulating gas replenishment of the pressure compartment. Test or re-fill equipment is connected via a standardised DN8 port during normal operation under nominal system pressure.


Products for gas density